This application claims the priority of Korean Patent Application No. 2004-104423, filed on Dec. 10, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a data call terminating service system and method for a dynamic IP (Internet Protocol) of a mobile communication terminal and, more particularly, to a technology for providing a data call terminating service using a dynamically assigned IP address of a mobile communication terminal.
2. Description of Related Art
Korean Unexamined Patent Application No. 2004-0026891 (Apr. 1, 2004) discloses a call terminating service method for a dynamic IP in an asynchronous mobile communication network (3GPP).
According to this method, GGSN (Gateway GPRS Support Node) of the asynchronous mobile communication network (3GPP) includes an inbound call controller, an IP management unit, a session management unit, and a dynamic domain name service (DDNS) server (which may be provided separately from the GGSN). The DDNS server checks whether or not there exists an IP corresponding to a domain name contained in an IP request message transmitted from a host. If it does not exist, the DDNS server sends an IP assignment request message to the inbound call controller. The inbound call controller transmits an IP reservation request message to the IP management unit. Upon receiving the IP reservation request message, the IP management unit reserves an IP and sends the IP to the inbound call controller. The inbound call controller sends the reserved IP to the DDNS server and acquires through HLR (Home Location Register) an address of SGSN (Serving GPRS Support Node) to which a subscriber belongs. The DDNS server transmits a response message containing the reserved IP to the host. Upon receiving the response message, the host sets the reserved IP as a destination and transmits traffic data to the GGSN to provide a data call terminating service.
Meanwhile, Korean Unexamined Patent Application No. 2002-0041105 (Jun. 1, 2002) discloses a call terminating service method for a dynamic IP in a synchronous mobile communication network (3GPP2).
According to this method, when an IP address of a mobile communication terminal is changed in a wireless communication system, HA (home agent) transmits a DNS update message to automatically register the changed IP address in place of the mobile communication terminal. As a result, a mobile IP terminal can use a call terminating service without updating the changed IP address to a DNS server or a website.
However, the method disclosed in Korean Unexamined Patent Application No. 2004-0026891 can be applied to an asynchronous mobile communication network (3GPP) but cannot be applied to a synchronous mobile communication network (3GPP2). Meanwhile, the method disclosed in Korean Unexamined Patent Application No. 2002-0041105 can be applied to a synchronous mobile communication network (3GPP2) but cannot be applied to an asynchronous mobile communication network (3GPP).
Further, the above-mentioned two methods can provide the call terminating service to a mobile communication terminal in an active state or a dormant state, but cannot provide it to a mobile communication terminal in an idle state.
The active state implies a state in which a traffic channel and a PPP session are established. The dormant state implies a state in which a PPP session is established but a traffic channel is not established. In these two states, since a connection for data transfer can be established between a mobile communication terminal and a mobile communication system, the mobile communication system can transfer data to the mobile communication terminal. Accordingly, the conventional methods can be applied to a mobile communication terminal in the active state or the dormant state. However, in case of the idle state where a traffic channel and a PPP session are not established, since the mobile communication system cannot request a data call connection from the mobile communication terminal (that is because the data call connection is established by request of the mobile communication terminal), the above-mentioned conventional methods cannot be applied to a mobile communication terminal in the idle state.
In case of VoIP (Voice over IP) service, for example, when a mobile communication terminal attempts to make a VoIP call origination to a mobile communication system, the VoIP service cannot be provided to a mobile communication terminal in an idle state from an external host.